SkLiteDL: control reuse by a single parameter

This simply caps the number of times a display list can be reused.
As this number goes up, the average amount of memory we cache goes up
and the expected number of mallocs per SkLiteDL::New() goes down.

This strategy does not need a hard-coded cap on how many display lists
to cache, or how big they can grow.

TBR=herb@google.com

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2226813002

Review-Url: https://codereview.chromium.org/2226813002

1 files changed, 1 insertions, 0 deletions

diff --git a/src/core/SkLiteDL.h b/src/core/SkLiteDL.h
index 132bc376c8..072672d7ef 100644
--- a/src/core/SkLiteDL.h
+++ b/src/core/SkLiteDL.h
@@ -85,6 +85,7 @@ private:
     void onDraw(SkCanvas*) override;
 
     SkLiteDL*          fNext;
+    int                fUsesRemaining;
     SkRect             fBounds;
     SkTDArray<uint8_t> fBytes;
 };